After two successive cuts, state -owned oil firms on Wednesday hiked jet fuel or ATF prices by 2.4 per cent in step with the firming international rates.Oil companies hiked aviation turbine fuel (ATF) prices by Rs 1,377 per kilolitre (kl), or 2.4 per cent, to Rs 57,843 per kl in Delhi with effect from midnight tonight, an official of Indian Oil Corp, the nation's largest fuel retailer, said.The hike comes after two reductions on 16th May and 1st June.In these two cuts, the first in over eight months, ATF prices had come down by Rs 4,094 per kl.ATF price in Mumbai, home to nation's busiest airport, was hiked by Rs 1,434 to Rs 58,601 per kl.Rate cuts on 16th May and 1st June had come after 14 successive hikes since October, 2010, when international crude oil prices started soaring.The ATF price in Delhi on 1st October, 2010 was Rs 40,728.52 per kl.The rates were increased by Rs 19,831.48 per kl, or 48.7 per cent till 30th April, when last price hike before Wednesday's was announced.No comment could be immediately obtained from airline companies on the impact of the price reduction on passenger fares.Fuel cost accounts for 40 per cent of the airlines' operating cost and rates vary from airport to airport depending upon the local sales tax.IOC and its sister public sector retailers Hindustan Petroleum Corp (HPCL) and Bharat Petroleum Corp (BPCL) revise jet fuel prices on the 1st and 16th of every month, based on the average international price in the preceding fortnight.